You're still confusing two constructions. There's no "or" in Google's message. They're doing to do what they're going to do, regardless of anyone else's actions. They're giving advance notice, but not an opportunity to change their plan.
It's the same distinction as between these two sentences:
"Give me your wallet or I'll drop this piano on you."
"I'm going to drop a piano, you might want to get out of the way."
The big difference here is "something is going to happen" vs. "something is going to happen to you". A threat or an ultimatum implies that you're the specific target of the action. An advertisement or notification implies that someone is going to take some action that may possibly affect you, but isn't specifically directed at you.
The boundaries get fuzzy when billion-dollar corporations get involved because they tend to wield a lot of power. However, most people would say that if you're a startup and a competing startup says "We're going to launch a new feature; better get ready", that's not an ultimatum. (As startups go, that's pretty damn polite.)
Using the passive voice here doesn't change the fact that the "something that is going to happen" is something that Google is going to do.
"You should give me your wallet or something is going to happen to you. Just a heads-up."